In the state of the art, there are a plurality of devices and apparatus to coil strip or sheet leaving the hot or cold rolling train, which perform their function more or less efficiently.
One type of coiling machine particularly used in the hot rolling of strip or sheet is the downcoiler, which includes at least two coiling mandrels arranged in sequence and below the plane on which the strip or sheet which has to be coiled passes.
This coiling system, although it is widely used, has problems both regarding the speed at which the coils are formed and also regarding the quality of the sheet obtained, especially in the case of products which are particularly thin.
In fact, in the case of thin strip or sheet, when the leading end is bent under the plane on which it is fed in order to be coiled onto the downcoiler, there may be problems caused in the quality of the product.
Moreover, coiling is not carried out in a repetitive manner since it is performed alternately on two downcoilers placed at different distances from the shears.
Another problem which is also linked to the thinness of the strip or sheet to be coiled is that the strip rubs against the runway which delivers it to the coiling machine, which can cause a deterioration in the surface quality of the strip or sheet.
Another problem is that with the systems known in the state of the art with a guide belt for initial winding, the winding speeds must necessarily remain low. A further problem is the lead-in of the strip during the initial winding step when thin strip is being produced.
A further disadvantage is the distance between the shears and downcoiler downstream due to the consequent dangers of blockages of the leading end of the rolled stock, and the problems of losing temperature due to radiance.
There is also the problem of the trailing end of the wound strip which knocks against the equipment during the braking step of the coil. It is also a problem to support the coiling mandrel as a cantilever.
A further problem is how to guide the strip without causing damage to the surface thereof.
The present applicants have designed, tested and embodied this invention to overcome the shortcomings of the state of the art by providing a functional and extremely efficient solution both operationally and in terms of the quality of the product.